User can recover account with recovery key

[holmesworcester]

Users should be able to create and manage recovery keys and use them, with an invite link from an admin, to completely recover access to an account (username, roles, DMs.)

These designs are currently a bit spread out. We should consolidate them, and they're probably overlap a lot with device linking and account creation generally.

Entering recovery key:

https://www.figma.com/design/mVPYWRKZ0wK3XSWkMhsS2Q/Suspend%2FRestore-(and-remove)?node-id=856-4650&t=Y15gEtGbPp12LMMO-4

Creating recovery key: https://www.figma.com/design/mVPYWRKZ0wK3XSWkMhsS2Q/Suspend%2FRestore-(and-remove)?node-id=862-11467&t=Y15gEtGbPp12LMMO-4

Prototypes:

Create account or recover

Home screen

[holmesworcester]

@jgaylor I think we could probably pause on this for now.

One note: many users are skeptical that they'd be able to keep a recovery code safe, so I think we'll emphasize device linking over recovery codes to start, and then maybe move to giving admins the ability to restore people, for groups who want that.